Virtually all automotive vehicles are provided with automotive air environment regulating systems, which almost always include heating systems, and also often include air conditioning systems. Virtually all such systems include a blower, driven by an electric motor, for circulating the air which is to be heated or cooled. Some systems include more than one blower. The amount of heat is generally regulated by a heat control valve which regulates the supply of hot liquid coolant from the engine to a heat exchanger which heats the air.
Most air conditioning systems are activated and deactivated by an electrically operable air conditioning clutch which is connected between an engine-driven pulley and an air conditioning compressor. The amount of cooled or heated air is usually controlled by changing the speed of the blower motor.
Typically, such systems include duct work containing movable doors or diverters for directing air into the passenger cabin through high or low outlets, and through windshield outlets which direct air against the windshield for defogging and defrosting purposes. Such doors or diverters are often operated by vacuum motors which selectively receive their motive power from the engine vacuum.
The present invention relates to control mechanisms for such systems. Such control mechanisms are generally of the type comprising three manually operable controls, including a manually movable selector control member, a manually movable heat control member, and a manually movable blower switch control member which operates the blower speed control switch.
The selector control is employed to select the function or functions to be performed by the system. For different systems, the selector control may have different numbers of positions, according to the complexity of the system. Thus, for example, a complex system may require seven positions to select seven functions, including OFF, MAXIMUM AIR CONDITIONING, NORMAL AIR CONDITIONING, BI-LEVEL AIR CONDITIONING, VENTILATION, HEAT, and DEFROST. For a less complicated system, the selector control may have five positions to select five functions, including OFF, AIR CONDITIONING, HEAT, HEAT WITH DEFROST, and DEFROST, for example. In a system without air conditioning, the selector control may select the five functions of OFF, VENTILATION, BI-LEVEL, HEAT and DEFROST, for example.
To select the various functions, the selector control member generally operates electrical switches, vacuum switches, or both, often combined into a single unit referred to as a vacuum-electric switch. Whatever the number of function positions, it is desirable to provide detent means for detaining the selector control in each of its function selecting positions.
In control systems for automotive heating and air conditioning system, the blower speed control switch is often operated by a manually operable lever or thumbwheel, which is manually operable to low, medium and high positions, and sometimes to other intermediate positions. Some systems employ only one blower motor and thus require only one blower speed control switch. Other systems employ two blower motors and thus require two blower speed control switches.
One object or accomplishment of the present invention is to provide a blower speed control mechanism in which the lever or thumbwheel is separate from the blower speed control switch or switches and is adaptable to operating either one or two switches. The mechanism prevents rattling of the control lever and is very inexpensive.
In accordance with the present invention, the object may be achieved by providing an automotive switching mechanism, comprising a supporting panel, a switch mounting bracket, means for securing such bracket to the rear side of such panel, at least one electrical switch mounted on such mounting bracket, and an operating lever confined between such bracket and such panel for operating such electrical switch, such panel having a slot therein, such lever having a manually operable portion extending forwardly through such slot and swingable therein, such lever having at least one operating arm projecting rearwardly therefrom, such electrical switch having a casing with a forwardly facing access slot for receiving such operating arm, such switch having a switching carriage movable in such casing and operable by such arm, such lever having rearwardly facing generally semicircular rocker shaft means thereon, such bracket having forwardly projecting bearing means thereon with generally semicircular bearing recess means for rockably receiving such rocker shaft means, such lever having a pair of forwardly facing tapered shaft elements with generally frustoconical curvature, such panel having a pair of rearwardly projecting flexible flanges for engaging such tapered shaft elements to retain such lever with such rocker shaft means pressed against such semicircular bearing recess means.
The operating lever may be of the thumbwheel type, having a thumbwheel portion projecting through the slot in the mounting panel.
Preferably, the flexible flanges are flexed by engagement with the tapered shaft elements, to provide a spring action, pressing the rocker shaft means against the semicircular bearing recess means. In this way, the flexible flanges prevent any rattling of the operating lever.
Preferably, the mounting panel is formed with a pair of additional guard flanges, projecting rearwardly therefrom into adjacent relation with additional shaft elements on the operating lever. The guard flanges may be substantially inflexible and are effective to limit forward movement of the lever so as to protect the flexible flanges from any possible breakage. The guard flanges are preferably spaced outwardly from the flexible flanges in a lateral direction. Preferably, the flexible flanges and the guard flanges are molded in one piece with the mounting panel and are made of a resilient resinous plastic material.